Electric-current controller



(N0 ModeL) 2- sheetssheet 1.

M. 0. SARGENT.

ELECTRIC CURRENT CONTROLLER.

No. 433,744. Patented Aug. 5-, 1890;

Wifnesses. k Ewen/022 Ww zflma (No Model.) 2 SheetsSheet 2.

M. 0. SARGENT.

ELEGTRIG CURRENT CONTROLLER. 1

No. 433,744. Patented Aug. 5, 1890.

Wit 06.5.56 3. [Tow/Z607, ifm/ who a W UNETED' STATES MILTON O. SARGENT, OF MALDEN, MASSACHUSETTS, ASSIGNOR FOURTIIS TO JAMES. N. GEORGE,

PATENT OFFICE.

OF THREE- OF PLAISTOVV, NEW HAMPSHIRE,

CHARLES A. STEARNS} OF XVATER'IOWN,AND- CHARLES L. ELY, OF

ERADFORD, MASSACHUSETTS.

ELECTRIC-CU RRENT CONTROLLER- SPECIFICATION forming part of Letters Patent No. 433,744, dated August 5. 1890.

Application filed May 20, 1890. Serial No. 352.469 (Ho model.)

To all whom it may concern.-

Be it known that I, MILTONO. SARGENT, re-

siding at Maiden, in the county of Middlesex the core being the result of the passage ofcurrents of electricitythrough the same, the coil and its core constituting a current-controller.

My invention also, relates to the application 'of such a device in combination with electrical circuits and instruments. I

I have shown my invention applied to the protection of electrical instruments from the abnormal or strong currents of electricity which are liable to traverse the wires of circuits arranged for low-intensity currents by reason of leakages from or crosses with wires carrying such abnormal or high-intensity currents and by reason of dangerous earthcurrents also.

The ordinary method of protection from abnormal currents-is to place between the line and the instruments to be protected 3. fusible wire,,which is relied upon to fuse. or blow out where such foreign currents come onto the line,'or-to place therein a magnetoelectric apparatus for shunting the instruments either by opening the line or by putting on a ground to convey the foreign current to'the earth. It has been found that whlle these devices are well enough for cases where powerful currents are used in the circuitsfo be protected,.they are not efii ient in. circuits using currents of comparatively low intensity. Thereal danger 'to' low-tension circuit instrumentsarises froniwhat are denominated sneak currents,' or those currents which can be safelycarried by'and-p'a'st .ceed to describe,

the fusible wire and which heat the fine wires of the in-strumentc'oils and destroy them before the fusible wire is fused or blown.

' In carrying out my invention I employ a fusible wire between the line and the instruments to he protected, asin the ordinary way, and in addition thereto insert between the fusible wire and the instruments 2. device which stops all currents, including thesneak currents, which are of higher intensity or greater volume than those for which the line and instruments arc-arranged to carry and to be operated by, I

and point out in the claims.

In the accompanying drawings, Figure 1 shows a line terminal embodying my inventions, and Fig. 2 is. a' diagram showing. my

all of which I will now pic.

method of protecting the instruments at an intermediate station on a' circuit. Fig. 3 is an enlarged view, and Fig. 4 a cross-section on line a; 00 thereof, of the circuit-controller shown in Fig. 1., 5 is an enlargedview of a modification of the circuit cont rollen Referring to Fig.1, w is the line-wire entering a terminal station at post 5, between which andpost 6 is a, fusible wire f; Front the post 6 the circuit extends to post 2, pro jectin g from the side of abox A, made of insulating material. The box A contains an arrangement of my improved circuit-changer, regulator, or controller. The post 2 extends through the wall and-intothe interior of the box. At its inner end is pivoted a metal '1e 8o ver 12, at 0, whose free end has upon its upper side a vcontact-pin'd. Directly over the pin dis a contact e, (preferably of carbon, to avoid the sticking occasioned by two metalcontacts'co'm'ing together,)on the inner end'of the post 4:, which projects from the top ofthe box.- The contacts at and care normally separated or open. 'A wire .10 extends'to the earth G. .Thefree end of the lever b rests upon the upper surface and end ofa curved flat metal tube'a, whose opposite end is socured tothe post, 3 by the screwf. This flat .tube is partly filled with alcoholor ether and 1S- hermeticallysealcdz- Around the lower of the post 2, and the otherv end extends toand is secured to the inner end of post 1,

which projects from the side of the box A wire '20 extends from the post 7 to the instru mcnt I to be protected, from which a wire goes to groundG. The metal tube it forms the core of the fine-wire coil 0, which normallyformsa portion of (and of higher resistance than) the main-linecircuit. Figs. 3 and lshow, enlarged, the circuiecontroller as composed of a coil of wire 0, and a central corea, in the form of a fiat tube, which is partially filled, as hereinbefoi'e described, with alcohol, ether, or other such fluid? The operation of the device is as follows: The ordinary currents of electricity to operate the instrument- I enter by wire w, fuse f, post 2, wire to to coil 0, thence to post 7 by wire w to instrument I and ground G. if by reason of leakage or a wire-cross a very heavy current comes in by wire 20, the fusible wire f is fused or blown out, and the circuit being opened the foreign current cannot reach the instrument 1; but if a sneak; current comes in by wire to which can be carried by the fusible wire f withoutfusing it, it passes by the wire 20 through the convolutions of the core 0,

sent a resis ance to the passage of the sneak current suficient to heatthe hollow metal core a, causing the inclosed liquid to expand.

In so doing tends to straighten out, and thereby lifts the lever b and forces its contaetpin d into con tact with the contact e, thus furnishing a shunt-circuit of lower resistance for the a foreign current to earth G by way of line '10, post 2, substance of lever b,contac,ts d and e, post 4, wire 20 to earth G", and-if the sneak current continues the fusible wire f fuses and opensthe circuit; but if the sneak cur.-

rent ceases before the fusible wire is fused the core-tube a cools down and resumes its normal shape, allowing the lever to drop and open the shunt eircuit, the instrument-circuit being thus automatically restored.

Instead of the any equivalent cOntact-makePT-as, for in stance, a metal spring attached by-yone end to the post 9. V I i Fig. 2 shows a modification of my inventron arranged at an intermediate station on a ClI'Cllll-u At terminal stations, as shown in Fig.1, the danger from high-tension or abnormal currents to a low-tension circuit is from one direction only-the line-entering side-but at intermediate stations the danger is from two directions or sources, 2'; e., the entering and departing line-wires.

In Fig. 2 the linc-wire 10 passes to post 5,

which, being of smaller diameter than the line-or fusible wire, prethe freecurved end of the tube pivoted lever b, I may use x core aand closed the contacts (Z and e,.shuntbetween which and post 6 is a fusible wire f. The line continues by wire 20, coilc, wire w, to instrument I to be protected, thence by wire a to post 12, between which and 13 is a fusible wire f, the 'line extending outward to'the next station by wire w Resting upon the curved upper part of the core-tube h is the pivoted lever b. Near its post pivot is a contact h, directly overwhich and 7-5 from each other by block 10. A wire 7 ex-.

tends from post 6 to spring 8, and niece wire 11 extends from post to s'pring 9.

The ordinary working-current of instrument I may enter from either side, keeping on wire 20 w 20 passing through fuses f f and coils I and 6 without disturbing the ad;

justment of the circuit; but suppose anneal: current to enter from the right side m the direction of the arrow, if it passes the fuse f it heats the core a of the coil 0, causing it to straighten and close the contact h with spring 3, and goes to ground at G by way of wire 7, spring 8, lever 1), spring 3, and wire 14, and maybe blows out the fuse f. If a sneak current comes in from the-left side in the direction of the dotted arrow it passes.

the fuse f through coils 'I to coil a, heating its core a, and thereby closing the contacts j with Hand '1, with 8, shunting the current byto ground, and possibly fusing the wire f In this example, although the sneak current wire 11, lever Li), and wire 14 passes through the coils I of the instrument, the core of coil cis so sensitive that a shunt is made thereby before the instrument-coils are injured.

1 do not limit myself to the described thermostatic core a, as I may use one composed of two differ'entially-expansible metals, as in Fig. 5, where the core of the coil is shown asso constructed, the form of the core being the same as shown in Fig. 2. To obtain the heat- 'ing effectthe wire of the coil need not vary much in size from the ordinary .oflice-wire used for making connections, as the convolutions of the coil create suflicieut resistance to produce the heat. of adj ustment.

- .I nsome cases it is'desirablc, when the lever 12 has been pushed up by the expansion of the lug theforeigu currents to ground, to maintain the ground-connection; To eifect this result l-provide means, as indicated in dotted and prevents the lever from falling down and This is, however, a matter opening the circuit, thus maintaining the shunt or ground circuit until manually broken.

I claim- 1. The combination of an electric-currentcontrolling device consisting of a coil of wire having a central metallic tubular core, partially filled with-fluid, as described, one end of which is secured to a support while its other end is free and curved, the said coil being normally in a main circuit, and a norinallyopen grounded branch circuit adapted to be closed by means of said core.

2. The combination,in an electric circuit, of a main line, a fusible wire, a current-controlling device consisting of a coil of wire forminga part of said main line,havi-ng a central metallic tubular core, partially filled with fluid, as describerhone end of said core being secured to a support while its other end is free and curved, electrical instruments in the said main line having a ground-wire, and a normally-open grounded branch cir cnit.

3. An electric-current-contro1ling device consisting of a coil'of wire having a central metallic tubular core partially filled with fluid. as described, one end of which is socured to a support while its otherend is free and curved, the said coil being normally ina main circuit, and a normally-open grounded branch circuit consisting of a contact-lever and a grounded wire,.one end of said lever being pivoted to a support in electrical connection with the said main circuit, its. other end resting by. gravity upon the free and curved end of said core and adapted to make electrical contact-with said grounded wire.

4. In an electric circuit, the combination of two fusible plugs, electrical instruments, a current-regulating device consisting of a coil having a thermostatic contact-regulatin g core, and two shunt-circuits composed of a normally-open contact-maker, and a ground-wire common to both shunt-circuits, and two shuntcircuit wires, as 7 and 11, as and for the purposes set forth.

In testimony whereof I have signed my name to this specification, in the presence-oftwo subscribing witnesses, this 19th day of May, A. D. 1890.

MILTON O. SARGENT.

Witnesses:

GEo. WILLIS PIERCE, FRANK C. Locxwoon. 

